Combined solvent treatment of phosphatide emulsion to break said emulsion and remove non-lipid substances



United States Patent COMBINED SOLVENT TREATMENT OF PHOS- PHATIDE EMULSION T0 BREAK SAID EMUL- SION AND REMOVE N ON -LllPID SUBSTANCES Douglas J. Hennessy, Teaneck, N.J., and Edward E. Kupstas, New York, N.Y., assignors to American Lecithin Company, Inc, Woodside, N.Y., a corporation of Ohio No Drawing. Application June 18, 1956 Serial No. 591,796

9 Claims. (Cl. 260-403) 'In the production of phosphatides including lecithin .from soy beans, corn germs, and other materials containing lecithin, there are produced aqueous emulsions, containing about 50 percent of phosphatides including a minor proportion. of fatty oil. These emulsions are difiicultly separable and it is common practice to remove the water by drying the oil-containing phosphatide emulsion at an elevated temperature under vacuum.

. 'The length of time required for dehydrating, and the cost, is directly related to the amount of water present. on the other hand, the heating of the phosphatide material in the presence of naturally contained carbohydrate substance causes a darkening in color probably as a result of a"browning reaction with amino groups contained in the phosphatides.

lt is among the objects of the present invention to provide a novel procedure for separating phosphatide emulsions and to secure the production of an enhanced novel phosphatide product of greater purity and improved ap pearance.

It is a particular objective of the present invention to provide a method of preparing phosphatides in which thephosphatides or lecithin is recovered with minimized change during dehydration.

It is a further object of this invention to treat the crude phosphatide emulsion containing some occluded or accompanying oil, as obtained in the degumming .of fatty oils, especially vegetable oils in such a way as to break the emulsion, reduce the water content of the phosphatide and to remove impurities which can be dissolved in or be washed out by water without, however, removing the fatty oil associated with the phosphatide.

Previous methods have involved the treatment of more or less pure lecithin and other phosphatidic material or treatment of crude forms of lecithin in such a way as to remove all or part of the associated fatty oils and further such methods have been based on different solvents and procedures and have been concerned with fractionation, or have been applied to heat dried substantially water free phosphatidic material whereas our invention is not concerned with fractionation of component phosphatides and is especially useful for the improvement of processing and the bonification of commercial oil containing phosphatidic material.

In the trade the term lecithin is used to refer to commercial oil containing phosphatide, such as derived from soybeans, corn germ or peanuts, or from cottonseed, flaxseed, etc., usually via degumming of the respective crude oil, which contains besides pure phosphatidyl choline (lecithin) other phosphatides such as phosphatidyl ethanolamine (cephalin) and inositol phosphatide, and unless otherwise qualified it is to be understood that the term lecithin is used herein in its broad connotation as commonly understood by those in the several trades and industries.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is 2,882,285 Patented Apr. 14, 195? 2 given by way of limitation, since various changes therein may be made by those skilled in the art without :departing from the scope and spirit of the present invention.

In accomplishing the above objects, .it has beenfound most satisfactory, according to one embodiment of the present invention, that phosphatides or lecithin aqueous emulsion may be readily separated or converted by addition thereto of combinations of water-miscible formamide or dimethyl formamide solvents and water immiscible chlorinated hydrocarbon solvents.

Among the water immiscible solvents which may be employed are ethylene chloride, trichlorethylene, methylene chloride, chloroform, carbon tetrachloride,aud tetrachlorethylene.

.Among the water miscible solvents are included form amide and dimethyl formamide.

Generally in proportionment to parts by weigh of emulsion there may be added 50 parts by weightof water immiscible solvent and 30 parts by weight :of water miscible solvent. I

For example, a suitable solvent combinationmay cousist of 20 parts by weight of trichlorethylene, 7 parts by weight of dimethyl formamide, and 7 parts by weight of ethyl alcohol. This composition may be entered into the emulsion by agitating.

It has been found that there is a separation of the emulsion in two layers, which they may be separated by standing or centrifuging or much more quickly by heating :to the boiling point of the lowest boiling ,solvent present after the addition of suflicient phosphoric acid or other acid to adjust the pH of the system to approximately 4.5;, and addition of a salt such as sodium chloride in ,an amount equal to 1% to 3% of the total lecithin emulsion still further decreased the time required .for.;sep,aration of phases. 1

Depending on density factors the phosphatide containing layer may be either upperor lower in diiferentformulations.

In the aqueous layer are removed non-lipid substances such as carbohydrates, minerals from the phosphatidesin the non-aqueous layer and there will be a concentration of the phosphatides in the non-aqueous layer. The fatty oil remains associated with the phosphatide.

Furthermore, the moisture content of the phosphatidie material in the non-aqueous layer is greatly reduced whereby subsequent dehydration is facilitated, while, prior to dehydration the keeping properties are improved ;in comparison with ordinary phosphatide emulsion.

The resultant phosphatides or lecithin may beheated up to 100 C. in drying without undue darkening-or charting and maintain their color. Moreover, :these phosphatides" will exhibit less frothing or gumminess.

To further improve the properties of the phosphatides; they may be washed further before drying'withlittle agi- ,tation with a wash water including, if desired, acid or salt as set forth above. This washing may be repeated two;or three times.

It .has been found that the resultant phosphatide or lecithin has a lower ash content and a greatly improved lecithin or phosphatide is produced.

It has been surprisingly observed that the treated phosphatidic material possesses enhanced afiinity for water and will emulsify in water more readily than ordinary oil containing phosphatide dried without the treatment herein described.

Example I ene and 25 parts of dimethylformamide and on centrifuging separated cleanly into two phases, a clear upper water n s AAA A phase and a yellow lower phosphatide containing phase. The lower layer was then evaporated by heating under reduced pressure.

- Example I] -As in Example I, using 50 parts of aqueous phosphatide emulsion as obtained in the degumming of phos phatide containing fatty oils and 20 parts of dimethyl formamide and 15 to 50 parts of trichlorethylene.

Example 111 184 parts of lecithin emulsion usually obtained by adding water or steam to crude phosphatide containing fatty oil, was treated with 7 parts of peracetic acid for 3 hours at 60 C. 92 parts of this was boiled with 92 parts of water-to'produce 140 parts of lecithin.

- This was shaken with 50 parts of-trichlorethylene and 35 parts of dimethyl formamide to produce a thick emulsion. The emulsion broke after standing minutes in a separatory funnel.

'The lower layer was removed and the solvent evaporated without further washing. The product was very stiff and prone to frothing during the removal of the solvent. To increase the fluidity while removing the solvent 15 parts of corn oil was added. The heat stability was better than that of ordinary lecithin. Browning did not take place until 160 C.

Having now particularly described and ascertained the nature of the invention, and in What manner the same is to be performed, what is claimed is:

- 1. A method of separating aqueous phosphatide emulsions which comprises combining therewith water miscible and water immiscible saturated, unsubstituted, liquid- 'at-room-temperature, organic solvents at the same time,

saidwater miscible solvent being selected from the group consisting of formamide and dimethyl formamide, and said water immiscible solvent being a low molecular Weight chlorinated hydrocarbon containing 1 to 2 carbon I containing 1 to 2 carbon atoms and 1 to 4 chlorine atoms.

3. A method of separating aqueous phosphatide emulsions which comprises combining therewith water miscible and water immiscible saturated, unsubstituted, liquidat-r'oom-temperature, organic solvents at the same time adjusting the pH to approximately 4.5, heating to just below the boiling point of the lower boiling solvent, followed by recovering the phosphatide-containing layer, said-water miscible solvent being selected from the group consisting of forrnarnide and dimethyl formamide, and said water immiscible solvent being a low molecular weight chlorinated hydrocarbon containing 1 to 2 carbon atoms and 1 to 4 chlorine atoms.

4. A method of separating aqueous phosphatide emulsions which comprises combining therewith water miscible and water immiscible saturated, unsubstituted, liquid-atroom-temperature, organic solvents at the same time and adding a small amount of salt to facilitate separation of the phosphatide-containing layer, said water miscible solvent being a low molecular weight chlorinated hydrocarand dimethyl formamide, and said water immiscible solvent being a lower molecular weight chlorinated hydrocarbon containing 1 to 2 carbon atoms and 1 to 4 chlorine atoms.

5. A method of separating aqueous phosphatide emulsions which comprises combining therewith water miscible and water immiscible saturated, unsubstituted, liquid-atroom-temperature, organic solvents at the same time followed by separating with the addition of sodium chloride in an amount equal to about 3% of the emulsion followed by separating and washing of the phosphatide-containing layer, said water miscible solvent being selected from the group consisting of formamide and dimethyl formamide, and said water immiscible solvent'being a low molecular Weight chlorinated hydrocarbon containing 1 to 2 carbon atoms and 1 to 4 chlorine atoms.

6. A method of separating phosphatide emulsions containing about 30% to 80% water which comprises combining therewith water miscible and water immiscible saturated, unsubstituted, liquid-at-room-temperature, organic solvents at the same time, said water miscible solvent being selected from the group consisting of formamide and dimethyl formamide, and said water immiscible solvent being a low molecular weight chlorinated hydrocarbon containing 1 to 2 carbon atoms and 1 to 4 chlorine atoms.

7. A process of separating a phosphatide emulsion which comprises mixing 50 parts of an ethylene chloride and 25 parts of a methyl formamide with 50 parts of an emulsion resultingfrom the water degumming of crude soybean oil containing 40 percent of water for 30 minutes,

" centrifuging to separate into a clear upper water phase and separating and evaporating the lower layer under reduced pressure.

8. The process of claim 7 adjusting before centrifuging to a pH of 4.5 and repeatedly washing before evaporating with a wash water containing an electrolyte.

9. A process of treating a phosphatide emulsion resulting from the water degumming of crude soya bean oil containing about 40% water and about lecithin, which comprises mixing the emulsion for about 30 minutes with about 50 parts by weight of trichlorethylene and about 25 parts by weight of dimethyl formamide and then centrifuging to separate the mixture into two phases, a clear upper water phase and a yellow lower phosphatide containing phase, and then separating and evaporating the lower layer by heating under reduced pressure.

References Cited in the file of this patent I UNITED STATES PATENTS 

1. A METHOD OF SEPARATING AQUEOUS PHOSPHATIDE EMULSIONS WHICH COMPRISES COMBINING THEREWITH WATER MISCIBLE AND WATER IMMISCIBLE SATURATED, UNSUBSTITUTED, LIQUIDAT-ROOM-TEMPERATURE, ORGANIC SOLVENTS AT THE SAME TIME, SAID WATER MISCIBLE SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF FORMAMIDE AND DIMETHYL FORMAMIDE, AND SAID WATER IMMISCIBLE SOLVENT BEING A LOW MOLECULAR WEIGHT CHLORINATED HYDROCARBON CONTAINING 1 TO 2 CARBON ATOMS AND 1 TO 4 CHLORINE ATOMS. 